1）注腸X線診断

Detailed Imaging Diagnosis for Early Colorectal Carcinomas─Barium Enema Study

要旨　過去10年間に，SM癌を疑う早期大腸癌473例に対して術前の精密検査として注腸X線検査を施行した．病変描出率は97.5％（461/473）と良好であった．深達度正診率は全体では72.1％とSM癌を疑う病変を中心に注腸X線検査を行ったため，さほど高い成績は得られなかった．深達度診断に有用なSM-m癌で有意に高頻度に出現する所見として，（1）隆起型では陥凹を認める，皺襞集中を認める，側面変形を認める，であり，（2）表面隆起型では皺襞集中を認める，LST（laterally spreading tumor）では陥凹を認める，側面変形を認める，で（3）表面陥凹型では深い陥凹，陥凹内に凹凸を認める，皺襞集中を認める，側面変形を認める，であった．これらの所見が1つ以上認められる病変ではSM垂直浸潤距離1,000μm以上のSM-m癌の可能性が高く，外科手術を考慮し，1つも認められないときには，内視鏡切除を行って，組織学的にリンパ節転移の危険性を判断して追加手術の是非を決定すると効率がよいと考えられた．

　Barium enema study was performed for a total 473 cases of early colorectal carcinomas as pretherapeutic detailed examination in the last 10 years. The lesion delineation rate was a satisfactory 97.5%（461/473）. Overall accuracy of invasion depth diagnosis was slightly lower at 72.1% because barium enema study proceeded mainly for lesions with suspected SM cancers. Useful radiographic findings for invasion depth diagnosis that frequently appeared in SM-m cancers are as follows ;（1）Polypoid type : presence of depression surface, folds converging toward the tumor, lateral wall deformity,（2）Flat elevated type : presence of folds converging toward the tumor, LST（laterally spreading tumor）: presence of depression surface, lateral wall deformity,（3）Slightly depressed type : presence of deep and/ or irregular depression surface, folds converging toward the tumor, lateral wall deformity. Therapeutic strategy on the basis of radiographic findings was as follows ; if at least one or more radiological findings is detected, the patient should be sent for surgery because the lesion may be a SM-m cancer with more than 1,000μm submucosal invasion distance, but if no radiological findings are delineated, the lesion may be endoscopically resected firstly, followed by additional surgery or not according to the histopathological findings.